page_title: IBM System/360
section_title: Basic hardware components
hierarchical_section_title: IBM System/360 / Technical description / Basic hardware components
caption_attribution_description: Solid Logic Technology card-holding board en:IBM en:computers in the en:System/360 era used en:hybrid circuits instead of the then new en:integrated circuits. IBM called this Solid Logic Technology (SLT). This photo shows a board from an en:IBM 1800 full of SLT printed circuit cards. The hybrid circuits are in the square metal cans. This photo was taken by Mike Ross of corestore.org . He has given permission via email: "Feel free to make use of ... my pictures under the GNU license. All I ask is that they are credited &amp; linked...]. --agr 18:55, 17 Aug 2004 (UTC)
context_page_description: The IBM System/360 is a family of mainframe computer systems that was announced by IBM on April 7, 1964, and delivered between 1965 and 1978. It was the first family of computers designed to cover the complete range of applications, from small to large, both commercial and scientific. The design made a clear distinction between architecture and implementation, allowing IBM to release a suite of compatible designs at different prices. All but the only partially compatible Model 44 and the most expensive systems use microcode to implement the instruction set, which features 8-bit byte addressing and binary, decimal and hexadecimal floating-point calculations.
  The launch of the System/360 family introduced IBM's Solid Logic Technology, a new technology that was the start of more powerful but smaller computers.
  The slowest System/360 model announced in 1964, the Model 30, could perform up to 34,500 instructions per second, with memory from 8 to 64 KB. High performance models came later. The 1967 IBM System/360 Model 91 could execute up to 16.6 million instructions per second.
context_section_description: Being uncertain of the reliability and availability of the then new monolithic integrated circuits, IBM chose instead to design and manufacture its own custom hybrid integrated circuits. These were built on 11 mm square ceramic substrates. Resistors were silk screened on and discrete glass encapsulated transistors and diodes were added. The substrate was then covered with a metal lid or encapsulated in plastic to create a "Solid Logic Technology" (SLT) module.
  A number of these SLT modules were then flip chip mounted onto a small multi-layer printed circuit "SLT card". Each card had one or two sockets on one edge that plugged onto pins on one of the computer's "SLT boards". This was the reverse of how most other company's cards were mounted, where the cards had pins or printed contact areas and plugged into sockets on the computer's boards.
  Up to twenty SLT boards could be assembled side-by-side (vertically and horizontally) to form a "logic gate". Several gates mounted together constituted a box-shaped "logic frame". The outer gates were generally hinged along one vertical edge so they could be swung open to provide access to the fixed inner gates. The larger machines could have more than one frame bolted together to produce the final unit, such as a multi-frame Central Processing Unit (CPU).
caption: Many SLT cards plugged into an SLT board.
exif: {}